As semiconductor materials for devices such as organic EL devices, organic thin film transistors, organic light-emitting sensors and the like, conjugated polymers are used, and above all, attention is focused on application thereof to polymer organic solar cells.
As a method for producing a conjugated polymer, there is known a method of coupling monomers by the use of a transition metal complex catalyst.
For example, there has been disclosed a method of obtaining a copolymer having an imidothiophene skeleton and a dithienocyclopentadiene skeleton according to a Stille coupling process that uses a homogeneous transition metal complex catalyst of tetrakis(triphenylphosphine)palladium(0) or tetrakis(triorthotolylphosphine)palladium(0) (PTL 1, NPL 1, NPL 2, NPL 3).
There has also been disclosed a method of obtaining a copolymer having a fluorene skeleton and a benzidine skeleton according to a Suzuki coupling process that uses a homogeneous transition metal complex catalyst of tetrakis(triorthotolylphosphine)palladium(0) or bis(1,5-cyclooctadiene)nickel(0) (PTL 2, PTL 3).
Further, there has been described a capability of employing a heterogeneous transition metal complex catalyst as a catalyst for use in a method of producing a conjugated polymer (PTL 2).